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Recent in vitro Models for the Blood-Brain Barrier
Published in Carla Vitorino, Andreia Jorge, Alberto Pais, Nanoparticles for Brain Drug Delivery, 2021
João Basso, Maria Mendes, Maria Ferreira, João Sousa, Alberto Pais, Carla Vitorino
The assembling of a microfluid BBB model involves the culturing of brain endothelial cells. These are not fenestrated and slightly overlap in a monolayer. They are also characterised by expressing tight junction proteins, such as claudins, occludins and junction adhesion molecules, and adherens junction proteins, including cadherin and vinculin [2]. Due to the specificity of these transmembrane proteins, they are often used as markers for a successful BBB formation [39]. As a consequence, these cells are close enough to one another to block paracellular diffusion of macromolecules, polar solutes and ions [2]. Furthermore, the expression of other membrane channels, transporters and enzymes also contributes to the formation of the physical and chemical barrier which secludes the CNS.
Microfluidics in Neuroscience
Published in Tuhin S. Santra, Microfluidics and Bio-MEMS, 2020
Pallavi Gupta, Nandhini Balasubramaniam, Kiran Kaladharan, Fan-Gang Tseng, Moeto Nagai, Hwan-You Chang, Tuhin S. Santra
One of the goals to carry out direct co-culturing is to investigate the roles of gap junctions, tight junctions, and desmosomes. Intercellular exchange of soluble molecules occurs between cells, and it is referred to as the gap junction mechanism. A tight junction occurs when cells are in close contact with one another. Tight junctions regulate the paracellular permeability, which is essential to establish compartments with different compositions in the body. Desmosomes are thread-like substances and are the main component in maintaining adhesive cell interactions. The main disadvantage of direct co-culture systems is that the effect of diffusible biomolecules secreted by one cell type on other cell types cannot be studied.
Nanomedicine for the Treatment of Neurological Disorders
Published in Sarwar Beg, Mahfoozur Rahman, Md. Abul Barkat, Farhan J. Ahmad, Nanomedicine for the Treatment of Disease, 2019
BBB is the major barrier to prevent crossing of most circulatory cells and other molecules from blood to brain. Along with pericytes, perivascular astrocytes, neurons, and basal lamina, microvessel epithelial cells form structural component of BBB (Bendayan et al., 2002; Obermeier et al., 2013; Zhao et al., 2015; Freese et al., 2017). This structure and transportation of endogenous compounds are maintained by tight junction and proteins present within it: claudins and occludin, along with adherent junction proteins (made up of cadherins and catenins) (Weksler et al., 2005). Other than these structural units, few specific efflux/influx channels, receptors, and protein transporters also act as metabolism-driven barrier at BBB; which includes ATP-Binding cassette (ABC) associated transporters, multidrug resistance-associated proteins (MRPs), P-glycoprotein (P-gp), and breast cancer resistance protein (BCRP, ABCG2), organic anion transporters (OATs) and organic anion transporting polypeptide family (OATPs), where OATs and OATPs act as both influx and efflux system for brain (Kusuhara and Sugiyama, 2001; Loscher and Potschka, 2005; Bendayan et al., 2006; Dallas et al., 2006).
Zinc(II)-Schiff base complex functionalized on gold nanospheres: synthesis, characterization, anticancer study and interaction with proteins
Published in Journal of Coordination Chemistry, 2022
Yin Zhuang Ng, Kong Wai Tan, Lip Yong Chung, Fatimah Salim, May Lee Low, Ing Hong Ooi, Foo Win Yip, Chew Hee Ng
The integrity of tight junction could be evaluated by measuring the transepithelial electrical resistance (TEER) across the monolayer [62]. The Caco-2 cells were grown in transwell insert for 21 days and the TEER value was monitored until it reached a plateau (between 55 and 60 Ω cm2), indicating the monolayer of Caco-2 cells had grown tightly to achieved tight junctions. For different treatment concentrations (lower than IC50), AuNS-TA-Zn(Sal) was added into the apical chamber. The TEER reading was monitored for each treatment at every 30-min interval for 3 h and the percent change from their initial TEER was plotted and shown in Figure 5.
Influences of simulated gastrointestinal environment on physicochemical properties of gold nanoparticles and their implications on intestinal epithelial permeability
Published in Journal of Environmental Science and Health, Part C, 2019
Xiumei Jiang, Xiaowei Zhang, Patrick Gray, Jiwen Zheng, Timothy R. Croley, Peter P. Fu, Jun-Jie Yin
Intestinal epithelial tight junction barrier dysfunction may lead to inflammation and mucosal injury.39,40 In this study differentiated Caco-2 cell monolayer was applied as a model of intestinal epithelial and exposed to GIT incubated Au NPs; the epithelial permeability was indicated by immunofluorescence staining of the tight junction protein ZO-1. As shown in Figure 5c, exposure to Au NPs of different sizes or 50 nm Au NPs incubated in different GIT fluids did not disrupt the tight junction in the Caco-2 cells, suggesting that Au NPs cause no damage to the intestinal epithelial permeability.